ELF exposure at work may influence risks for dementia, Parkinson's

May 5, 2017Clinical Essentials from Int Arch Occup Environ Health
CURATED BY Susan London

Takeaway 

• Men with higher occupational exposure to extremely low frequency (ELF) magnetic fields had an elevated risk for dementia and trends toward elevated risks for motor neuron disease, multiple sclerosis (MS), and epilepsy.

Why this matters

• Previous studies of ELF exposure and neurologic disease have had fairly short follow-up.

Key results 

• Compared with men in the general population who had never worked at the utilities, men with medium ELF exposure (0.1-0.99 µT) had a trend toward an elevated risk for motor neuron disease (incidence rate ratio, 1.24) and a significantly reduced risk of Parkinson's disease (0.81).
• Men with high ELF exposure (≥1.0 µT) had a significantly elevated risk for dementia (incidence rate ratio, 1.44) and trends toward elevated risks for motor neuron disease (1.78), MS (1.40), and epilepsy (1.34).
• Findings were mixed when the comparator was instead men within the cohort having a lower level of exposure.

Study design

• A cohort study of 32,006 male employees of 99 Danish electrical utility companies.
• Main outcomes were risks for neurologic disorders during a mean follow-up of 20.8 y.
• Funding: Danish Energy; Danish Cancer Society.

Limitations

• The registry identified only cases with hospital contact.
• Findings may have been affected by confounding.
• References
Pedersen C, Poulsen AH, Rod NH, Frei P, Hansen J, Grell K, Raaschou-Nielsen O, Schüz J, Johansen C. Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers. Int Arch Occup Environ Health. 2017 Apr 20 [Epub ahead of print]. doi: 10.1007/s00420-017-1224-0. PMID: 28429106


https://www.univadis.com/viewarticle/elf-exposure-at-work-may-influence-risks-for-dementia-parkinson-s-516249?s1=news


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Abstract


PURPOSE: 
Evidence of whether exposure to extremely low-frequency magnetic fields (ELF-MF) is related to central nervous system diseases is inconsistent. This study updates a previous study of the incidence of such diseases in a large cohort of Danish utility workers by almost doubling the period of follow-up.
METHODS: 
We investigated the risks for dementia, motor neurone disease, Parkinson disease, multiple sclerosis and epilepsy among 32,006 men employed at the 99 utility companies that supplied Denmark with electricity during the period 1900-1993. Cases were identified in the Danish National Patient Registry and the cohort was followed during 1982-2010. Exposure was estimated from a job-exposure matrix based on company records of job title and area of work and cohort members were allocated to one of three categories (<0.1, 0.1-0.99 and ≥1.0 µT).
RESULTS: 
For dementia, multiple sclerosis and epilepsy the incidence rate ratios (IRR) were close to unity, but higher for motor neurone disease [IRR 1.24, 95% confidence interval (CI) 0.86-1.79] and lower for Parkinson disease (IRR 0.81, 95% CI 0.67-0.97) among workers exposed to ≥0.1 µT compared with the Danish population. For the highest level of exposure (≥1.0 µT), IRRs of 1.44, 1.78, 1.40 and 1.34 were observed for dementia, motor neurone disease, multiple sclerosis and epilepsy, respectively.
CONCLUSIONS: 
We observed elevated risks of dementia, motor neurone disease, multiple sclerosis and epilepsy and lower risks of Parkinson disease in relation to exposure to ELF-MF in a large cohort of utility employees.
KEYWORDS: 
Central nervous system disease; Cohort study; ELF-MF; Occupational exposure
PMID:
 
28429106
 
DOI:
 
10.1007/s00420-017-1224-0


https://www.ncbi.nlm.nih.gov/pubmed/28429106